Hondata

Disclaimer: I'm not a tuning expert and trying to learn :)

I recently had a shop install a new XDI HPFP + DW300C LPFP. First WOT, the HPFP stopped functioning and threw P0089 DTC. I'm trying to debug now, but even after clearing the P0089 DTC, reflashing, etc, datalogging shows that Fuel Pump Duty Cycle is stuck at 100%, even when I first turn on electricity without trying to start the engine.

As far as I can tell, the HPFP doesn't have a position sensor or anything for the regulation solenoid. Which leads me to believe that the Fuel Pump Duty Cycle is a commanded value and not a measured value. So A) can anybody confirm this and B) if it is purely a commanded value, what would cause it to be stuck at 100% even with no active DTCs?

Thanks!

Have you paid to get the high-pressure pump functionality enabled?

Yes, entered the serial code and verified in Flashpro that it is enabled.

Did you also make sure that you have this enabled in the calibration you are using?

My tuner (Derek at IMW ftw) double checked for me and verified that the new calibration was correct for all the upgrades.

FYI, I just removed the new XDI HPFP and it looks like its bound up :(

The longer story behind this is that the tuning shop that installed the new DW300C LPFP installed it incorrectly, resulting in a sudden loss in pressure from the tank. They didn't add the spacer to the LPFP output before putting the o-rings on, so under high pressure the pump popped out of the fitting. When I took the LPFP housing out, the pump fell right out of the casing. I'm assuming the HPFP didn't last long without fuel to cool it and it bound up. I'm going to send the HPFP back to XDI for repair on the shop's dime.

So I'm assuming that the fuel pump duty cycle was just maxed out because DIFP wasn't tracking DICMD at all as it increased. But still interesting that it stays at 100% when just turning the electricity on and no engine. Would still like confirmation if possible that this is expected behavior from the ECU.

Try putting the stock pump back in and see if it works as it should.